Association of non-HDL cholesterol with subclinical atherosclerosis in HIV-positive patients

Association between the triglyceride to high-density lipoprotein cholesterol ratio and cardiovascular diseases in people living with HIV: Evidence from a retrospectively cohort study 2005-2022

INTRODUCTION

The triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, a novel biomarker for metabolic syndrome (MetS), has been validated in the general population as being significantly correlated with cardiovascular disease (CVD) risk. However, its capabilities to predict CVD in people living with HIV (PLWH) remain underexplored.

METHODS

We conducted a retrospective cohort study of 16,081 PLWH who initiated antiretroviral therapy (ART) at the Third People's Hospital of Shenzhen (China) from 2005 to 2022. The baseline TG/HDL-C ratio was calculated as TG (mmol/L) divided by HDL-C (mmol/L). We employed a multivariate Cox proportional hazards model to assess the association between the TG/HDL-C ratio and CVD occurrence, using Kaplan-Meier curves and log-rank tests to compare survival distributions. The increase in prediction risk upon the addition of the biomarker to the conventional risk model was examined through the assessment of changes in net reclassification improvement (NRI) and integrated discrimination improvement (IDI). Nonlinear relationships were investigated using a restricted cubic spline plot, complemented by a two-piecewise Cox proportional hazards model to analyze threshold effects.

RESULTS

At the median follow-up of 70 months, 213 PLWH developed CVD. Kaplan-Meier curves demonstrated a significant association between the increased risk of CVD and a higher TG/HDL-C ratio (log-rank P <0.001). The multivariate-adjusted Cox proportional hazards regression model indicated that the CVD hazard ratios (HR) [95% confidence intervals (95% CI)] for Q2, Q3, and Q4 versus Q1 of the TG/HDL-C ratio were 2.07 (1.24, 3.45), 2.17 (1.32, 3.57), and 2.20 (1.35, 3.58), respectively (P <0.05). The consideration of the TG/HDL-C ratio in the model, which included all significant factors for CVD incidence, improved the predictive risk, as indicated by the reclassification metrics (NRI 16.43%, 95%CI 3.35%-29.52, P = 0.014). The restriction cubic spline plot demonstrated an upward trend between the TG/HDL-C ratio and the CVD occurrence (P for non-linear association = 0.027, P for overall significance = 0.009), with the threshold at 1.013. Significantly positive correlations between the TG/HDL-C ratio and CVD were observed below the TG/HDL-C ratio threshold with HR 5.88 (95% CI 1.58, 21.88, P = 0.008), but not above the threshold with HR 1.01 (95% CI 0.88, 1.15, P = 0.880).

CONCLUSION

Our study confirms the effectiveness of the TG/HDL-C ratio as a predictor of CVD risk in PLWH, which demonstrates a significant nonlinear association. These findings indicate the potential of the TG/HDL-C ratio in facilitating early prevention and treatment strategies for CVD among PLWH.

Potential role of Lu/BCAM in HIV-related atherosclerosis

Atheromatous lesions are formed by macrophages and low-density lipoprotein cholesterol invading the vascular intima. Here we show that increasing cholesterol levels are associated with peripheral monocyte depletion and this imbalance is aggravated by carriage of Lu/BCAM leukocyte adhesion molecules. This is true only in HIV infection and probably explains the risk of atherosclerosis observed in HIV-positive patients.

Low-density lipoprotein cholesterol response after statin initiation among persons living with human immunodeficiency virus

BACKGROUND

Meta-analyses of general population studies report mean low-density lipoprotein cholesterol (LDL-C) reductions of 30% to <50% with moderate-intensity and ≥50% with high-intensity statins. Persons living with human immunodeficiency virus (PLWH) are at high risk for atherosclerotic cardiovascular disease (ASCVD), yet many have elevated LDL-C.

OBJECTIVE

To evaluate LDL-C response after statin initiation among PLWH.

METHODS

We conducted a retrospective cohort study of PLWH initiating statins between 2009 and 2013 (N = 706). Patients were categorized into mutually exclusive groups in the following hierarchy: history of coronary heart disease (CHD), diabetes, prestatin LDL-C ≥190 mg/dL, 10-year predicted ASCVD risk ≥7.5%, and none of the above (ie, unknown statin indication). The primary outcome was a ≥30% reduction in LDL-C after statin initiation.

RESULTS

Among patients initiating statins, 5.8% had a history of CHD, 13.6% had diabetes, 6.2% had LDL-C ≥190 mg/dL, 35.4% had 10-year ASCVD risk ≥7.5%, and 39.0% had an unknown statin indication. Among patients with a history of CHD, 31.7% achieved a ≥30% LDL-C reduction compared with 25.0%, 59.1%, and 33.9% among those with diabetes, LDL-C ≥190 mg/dL, and 10-year ASCVD risk ≥7.5%, respectively. In multivariable adjusted analyses and compared to patients with an unknown statin indication, LDL-C ≥ 190 mg/dL was associated with a prevalence ratio for an LDL-C reduction ≥30% of 1.81 (95% confidence interval, 1.34-2.45), whereas no statistically significant association was present for history of CHD, diabetes, and 10-year ASCVD risk ≥7.5%.

CONCLUSION

A low percentage of PLWH achieved the expected reductions in LDL-C after statin initiation, highlighting an unmet need for ASCVD risk reduction.

Body Composition and Metabolic Syndrome Components on Lipodystrophy Different Subtypes Associated with HIV

HIV-associated lipodystrophy syndrome (HALS) is characterized by body fat redistribution as a consequence of the antiretroviral therapy (ART) introduction, associated with an increased risk of cardiovascular disease development. Subjective diagnosis, classified between three subtypes according to the body region on which fat is lost and/or accumulated, named lipoatrophy, lipohypertrophy, and mixed lipodystrophy, is possibly accompanied with metabolic alterations. Forty people living with HIV/AIDS (PLHA), with clinical diagnosis of HALS and from both genders, were assessed. They performed ambulatorial follow-up and used ART regularly. The main findings were greater lipid profile alterations among women, while no metabolic profile differences were found between the HALS subtypes. The lipohypertrophy group showed major alterations, with higher values for total body fat percent, visceral fat area (VFA), body mass index (BMI), and abdominal and neck circumferences when compared to the other groups. Lean body mass was superior only compared to the mixed lipodystrophy group, and fat mass only compared to the lipoatrophy group. BMI showed strong correlation with the VFA. In conclusion, despite anthropometric alterations related to HALS these individuals present, those are not accompanied with metabolic alterations. Strategies, as behavioral changes and disorders prevention, are important to decrease the risk of cardiovascular disease development.

A Meta-Analysis of the Metabolic Syndrome Prevalence in the Global HIV-Infected Population

BACKGROUND

Cardio-metabolic risk factors are of increasing concern in HIV-infected individuals, particularly with the advent of antiretroviral therapy (ART) and the subsequent rise in longevity. However, the prevalence of cardio-metabolic abnormalities in this population and the differential contribution, if any, of HIV specific factors to their distribution, are poorly understood. Therefore, we conducted a systematic review and meta-analysis to estimate the global prevalence of metabolic syndrome (MS) in HIV-infected populations, its variation by the different diagnostic criteria, severity of HIV infection, ART used and other major predictive characteristics.

METHODS

We performed a comprehensive search on major databases for original research articles published between 1998 and 2015. The pooled overall prevalence as well as by specific groups and subgroups were computed using random effects models.

RESULTS

A total of 65 studies across five continents comprising 55094 HIV-infected participants aged 17-73 years (median age 41 years) were included in the final meta-analysis. The overall prevalence of MS according to the following criteria were: ATPIII-2001:16.7% (95%CI: 14.6-18.8), IDF-2005: 18% (95%CI: 14.0-22.4), ATPIII-2004-2005: 24.6% (95%CI: 20.6-28.8), Modified ATPIII-2005: 27.9% (95%CI: 6.7-56.5), JIS-2009: 29.6% (95%CI: 22.9-36.8), and EGIR: 31.3% (95%CI: 26.8-36.0). By some MS criteria, the prevalence was significantly higher in women than in men (IDF-2005: 23.2% vs. 13.4, p = 0.030), in ART compared to non-ART users (ATPIII-2001: 18.4% vs. 11.8%, p = 0.001), and varied significantly by participant age, duration of HIV diagnosis, severity of infection, non-nucleoside reverse transcriptase inhibitors (NNRTIs) use and date of study publication. Across criteria, there were significant differences in MS prevalence by sub-groups such as in men, the Americas, older publications, regional studies, younger adults, smokers, ART-naïve participants, NNRTIs users, participants with shorter duration of diagnosed infection and across the spectrum of HIV severity. Substantial heterogeneities across and within criteria were not fully explained by major study characteristics, while evidence of publication bias was marginal.

CONCLUSIONS

The similar range of MS prevalence in the HIV-infected and general populations highlights the common drivers of this condition. Thus, cardio-metabolic assessments need to be routinely included in the holistic management of the HIV-infected individual. Management strategies recommended for MS in the general population will likely provide similar benefits in the HIV-infected.

Pro-Inflammatory Markers in Relation to Cardiovascular Disease in HIV Infection. A Systematic Review

Background

In the past years many inflammatory markers have been studied in association with clinically manifest cardiovascular disease (CVD) and carotid intima-media thickness (CIMT) in HIV-infected patients, to obtain insights in the increased cardiovascular risk observed in HIV infection. This systematic review provides an oversight of the current knowledge.

Methods

A search was performed in PubMed, Embase and Cochrane in July 2014, identifying all articles from 1996 onwards addressing the relation between inflammatory markers and CVD or CIMT in HIV-positive adults. Two authors, using predefined criteria, independently conducted the selection of articles, critical appraisal and extraction of the data. Analysis was focused on the immune markers that were most frequently assessed. The review protocol was registered in the PROSPERO database at 11 July 2014 (registration number CRD42014010516). This review was performed according to the PRISMA guideline.

Findings

Forty articles were selected; eight addressing cardiovascular disease (CVD) and thirty-two addressing CIMT. C-reactive protein (CRP), interleukin-6 (IL-6) and d-dimer were assessed most frequently in relation to the occurrence of CVD; in four out of eight studies. All three markers were positively related to CVD in three out of four studies. Studies addressing CIMT were too heterogeneous with respect to patient populations, inflammatory markers, CIMT measurement protocols and statistical methods to allow for a formal meta-analysis to obtain summary statistics. CRP, IL-6 and soluble vascular cell adhesion molecule (sVCAM-1) were the most studied markers in relation to CIMT. None of the inflammatory markers showed an association with CIMT.

Interpretation

This review showed a relation between some inflammatory markers and CVD, however, no consistent relation is observed for CIMT. Statistical approaches that yields effect estimates and standardized CIMT protocols should be chosen. Further research should focus on prospective studies and a selected set of inflammatory markers.

Toll-like receptor 7 promotes the apoptosis of THP-1-derived macrophages through the CHOP-dependent pathway

Macrophage apoptosis is a prominent characteristic of advanced atherosclerotic plaques and leads to plaque destabilization. Certain studies have confirmed that influenza virus A (IVA) infection is related to acute myocardial infarction (AMI). However, it remains unknown as to whether this phenomenon is associated with Toll-like receptor (TLR)7, since single-stranded RNA (ssRNA) of IVA is a natural ligand of TLR7. Thus, in the present study, THP-1‑derived macrophages were infected with IVA or treated with imiquimod (IMQ) in the presence or absence of pre-treatment with oxidized low-density lipoprotein (oxLDL). The macrophages were pre-treated with oxLDL (5 µg/ml) for 24 h to mimic high lipid conditions. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazol-2-y-1)‑2,5-diphenyl-2H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. Our results revealed that TLR7 played an important role in macrophage apoptosis and cytokine secretion. Both IVA infection and IMQ treatment increased TLR7 expression, as well as the secretion of pro-inflammatory cytokines [interleukin (IL)-6, monocyte chemotactic protein (MCP)-1] and apoptosis. However, this increase in cytokine secretion occurred independently of cell apoptosis. oxLDL had potential synergistic pro-apoptotic effects combined with TLR7 activation. To determine whether endoplasmic reticulum (ER) stress plays a role in cell apoptosis, the mRNA and protein expression of known markers of ER stress [glucose-regulated protein (GRP)78 and C/EBP homologous protein (CHOP)] was detected by reverse transcription PCR (RT-PCR), quantitative reverse transcription PCR (qRT-PCR) and western blot analysis. Our results revealed that apoptosis aggravated ER stress, as shown by the overexpression of the pro-apoptotic sensor, CHOP. In conclusion, our study demonstrates the converging role of oxLDL pre-treatment, IVA infection and IMQ in ER stress-induced cell apoptosis.

Metabolic syndrome predicts all-cause mortality in persons with human immunodeficiency virus

We examined the association between metabolic syndrome (MS) and its individual defining criteria on all-cause mortality in human immunodeficiency virus (HIV)-infected persons. We used data from 567 HIV-infected participants of the Nutrition for Healthy Living study with study visits between 9/1/2000 and 1/31/2004 and determined mortality through 12/31/2006. MS was defined using modified National Cholesterol Education Program guidelines. Cox proportional hazards for all-cause mortality were estimated for baseline MS status and for its individual defining criteria. There were 83 deaths with median follow-up of 63 months. Baseline characteristics associated with increased risk of mortality were: older age in years (univariate hazard ratio [HR] 1.04, p<0.01), current smoking (HR 1.99, p=0.02), current heroin use (HR 1.97, p=0.02), living in poverty (HR 2.0, p<0.01), higher mean HIV viral load (HR 1.81, p<0.01), and having a BMI <18 (HR 5.84, p<0.01). For MS and its criteria, only low HDL was associated with increased risk of mortality on univariate analysis (HR 1.84, p=0.01). However, metabolic syndrome (adjusted HR 2.31, p=0.02) and high triglycerides (adjusted HR 3.97, p<0.01) were significantly associated with mortality beyond 36 months follow-up. MS, low HDL, and high triglycerides are associated with an increased risk of mortality in HIV-infected individuals.

Association of subclinical atherosclerosis with lipid levels amongst antiretroviral-treated and untreated HIV-infected women in the Women's Interagency HIV study

OBJECTIVE

We examined serum lipids in association with carotid artery intima-media thickness (CIMT) in HIV-infected and HIV-uninfected women.

METHODS

In 2003-4, among 1827 Women's Interagency HIV Study participants, we measured CIMT and lipids (high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), total cholesterol (TC), non-HDL-c). A subset of 520 treated HIV-infected women had pre-1997 lipid measures. We used multivariable linear regression to examine associations between lipids and CIMT.

RESULTS

In HIV-uninfected women, higher TC, LDL-c and non-HDL-c were associated with increased CIMT. Among HIV-infected women, associations of lipids with CIMT were observed in treated but not untreated women. Among the HIV-infected women treated in 2003-4, CIMT was associated both with lipids measured a decade earlier in infection, and with late lipid measurements.

CONCLUSION

Among HIV-infected women, hyperlipidemia is most strongly associated with subclinical atherosclerosis in treated women. Among treated women, the association appeared strongest early in the disease course.

Association of influenza virus infection and inflammatory cytokines with acute myocardial infarction

OBJECTIVE

To explore the potential relationship between previous influenza virus (IV) infection and acute myocardial infarction (AMI), and the mechanism of atherosclerosis, we conducted a case-control study and examined inflammatory cytokines to assess the association of previous IV infection and AMI.

METHODS

A questionnaire-based survey was conducted to collect information about demographic characteristics and heart disease risk factors. Fasting blood samples were obtained to measure immunoglobulin (Ig) G antibodies to influenza virus A (IV-A), influenza virus B (IV-B), cytomegalovirus, herpes simplex virus type-1 and type-2, adenovirus, rubella virus and Chlamydia pneumoniae, and to measure the level of certain biochemistry markers: interleukin-2, 6, 10 and 18 (IL-2, 6, 10 and 18), tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), endothelin-1 (ET-1), soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1).

RESULTS

Compared with the controls, the cases were more likely to have positive IgG antibodies to IV-A and IV-B [IV-A: odds ratio (OR): 3.1, 95% confidence interval (CI): 1.5-6.4; IV-B: OR: 10.2, 95% CI: 5.7-20.0]. After adjustment for potential confounding variables, the risk of AMI was still associated with the presence of IgG antibodies to IV-A (adjusted OR: 5.5, 95% CI: 1.3-23.0) and IV-B (adjusted OR: 20.3, 95% CI: 5.6-40.8). The levels of IL-2, 6, 10 and18, TNF-α, IFN-γ, ET-1, sICAM-1 and sVCAM-1 in patients with AMI were significantly higher than those of the controls (P < 0.01).

CONCLUSIONS

Our study supports the hypothesis that previous IV infection is associated with AMI. Inflammatory cytokines may take part in the development of atherosclerosis and trigger the occurrence of AMI.

Prevalence of metabolic syndrome among human immunodeficiency virus-infected subjects is widely influenced by the diagnostic criteria

BACKGROUND

The aim of this study was to compare the prevalence of metabolic syndrome in human immunodeficiency virus (HIV)-infected patients treated with highly active antiretroviral therapy (HAART), using the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III), European Group for the Study of Insulin Resistance (EGIR), and International Diabetes Federation (IDF) definitions.

METHODS

A cross-sectional study was carried out with 159 consecutive adult HIV-infected subjects (120 males and 39 females) under HAART. Anthropometric and laboratory parameters were measured by standard methods. Hyperinsulinemia was defined by a fasting concentration >75th percentile of values obtained in healthy individuals (107.5 pmol/L).

RESULTS

The prevalence of ATP III-defined metabolic syndrome was 10.1%; it was 28.3% according to EGIR criteria and 15.1% using the IDF definition. The concordance between the definitions was low (kappa coefficient ranging between 0.134 and 0.296). All subjects with EGIR-defined metabolic syndrome had hyperinsulinemia, but only 50% of those with ATP III-defined metabolic syndrome and 62.5% in the IDF metabolic syndrome population had hyperinsulinemia.

CONCLUSIONS

The inclusion of hyperinsulinemia as a criterion in the EGIR metabolic syndrome definition made it more discriminative than the ATP III definition, both in men and women, and than the IDF definition in men to identify metabolic syndrome in HIV-infected subjects under HAART.

A dedicated screening program for geriatric HIV-infected patients integrating HIV and geriatric care

BACKGROUND

Clinicians caring for HIV-infected patients >60 years old encounter multiple clinical challenges. The use of a functional geriatrics screening for detection of significant comorbidities is important in this population.

METHODS

The geriatrics screening evaluated functional capabilities, depression, cognitive dysfunction, nutrition, mobility, medicines used, and interactions.

RESULTS

As of July 2009, 57 patients were screened (average age 62.6, 39 males and 18 females). A total of 17 patients (9 males and 8 females) were referred to the geriatrics/HIV program because of identified problems in multiple domains: 10 with cognitive dysfunction, 8 with problems in basic or instrumental activities of daily living, 6 with nutritional issues, 5 with depression, 5 with mobility problems, 4 with visual issues, and 2 with hearing difficulties. The average age was 62.9. Median CD4 count and viral load were 285 (15-714) cells/mm(3) and 30 505 copies/mL (0-407 697), respectively.

CONCLUSIONS

The functional yearly screening of patients >60 years with HIV needs to be part of regular care of patients infected with HIV as multiple functional problems can be diagnosed and addressed.

Lipid abnormalities in a never-treated HIV-1 subtype C-infected African population

Dyslipidemia has been documented worldwide among human immunodeficiency virus-infected (HIV) individuals and these changes are reminiscent of the metabolic syndrome (MetS). In South Africa, with the highest number of HIV infections worldwide, HIV-1 subtype C is prevalent, while HIV-1 subtype B (genetically different from C) prevails in Europe and the United States. We aimed to evaluate if HIV infection (subtype C) is associated with dyslipidemia, inflammation and the occurrence of the MetS in Africans. Three hundred newly diagnosed HIV-infected participants were compared to 300 age, gender, body mass index and locality matched uninfected controls. MetS was defined according to the Adult Treatment Panel III (ATP III) and International Diabetes Federation (IDF) criteria. The HIV-infected group showed lower high density lipoprotein cholesterol (1.23 vs. 1.70 mmol/L) and low density lipoprotein cholesterol (2.60 vs. 2.80 mmol/L) and higher triglycerides (1.29 vs. 1.15 mmol/L), C-reactive protein (3.31 vs. 2.13 mg/L) and interleukin 6 (4.70 vs. 3.72 pg/L) levels compared to the uninfected group. No difference in the prevalence of the MetS was seen between the two groups (ATP III, 15.2 vs. 11.5%; IDF, 21.1 vs. 22.6%). This study shows that HIV-1 subtype C is associated with dyslipidemia, but not with a higher incidence of MetS in never antiretroviral-treated HIV-infected Africans.

Dyslipidemia following kidney transplantation: diagnosis and treatment

Lipid abnormalities are a common complication of kidney transplantation, occurring in up to 60% of patients. In fact, impairment of lipid metabolism is often present before renal transplantation due to the uremic state. After transplantation and recovery of renal function, lipid disturbances usually persist but show a different profile due to the various effects of immunosuppressive drugs on lipid metabolism. Actually, steroids, calcineurin inhibitors, and mammalian target of rapamycin inhibitors usually lead to quantitative and qualitative abnormalities of very low-density, low-density, and high-density lipoproteins. As cardiovascular diseases remain the leading cause of death in renal transplant recipients, management of dyslipidemia and other traditional risk factors, such as smoking, arterial hypertension, diabetes mellitus, and obesity, is of great importance to prevent cardiovascular complications and chronic allograft dysfunction. This review addresses the causes of dyslipidemia, the role of immunosuppressive drugs, and current recommendations to manage lipid disorders in renal transplant recipients.